June Gardening Tips

Pots & Borders

Put up hanging baskets for colour and scent all summer.

Winter flowering Pansies and spring flowering Wallflowers should be replaced with summer flowering bedding plants now. They may still have some blooms but they will quickly look scruffy as temperatures climb during summer.

Lift and divide clumps of primroses and polyanthus. Heel them in a shady place for summer and they can be replanted in your borders again in autumn.

If you want to raise your own border perennials then several really popular varieties should be sown now. Sow Delphiniums, Lupins and Foxgloves but keeping them cool will help germination at this time of year.

Pick Sweet Peas regularly so that they are not allowed to set seed. As soon as seeds form the flowers will get smaller and there will be less produced. If you have too many, give them away to your neighbours!

If you didn’t add slow release fertiliser [such as Osmocote] to the compost in your tubs and baskets, you will need to start regular liquid feeding now. Miracle Gro and Phostrogen Plant Food are ideal, just follow the instructions on the pack for dilution rate and frequency.

Sow Wallflower, Brompton Stock and Sweet William seeds in drills for bedding out in the autumn. This later than recommended sowing here in the West Country pays off with better quality plants.

Plant out Cannas and Dahlias. They both enjoy rich soil.

Stake tall plants to give them support.

Cut flower stems off Euphorbias as they become straw coloured. Take care to cover your skin against the sap of this plant as it can cause irritation.

Trees, Shrubs, Roses, Conifers, etc.

New shoots on any climbers, but Clematis in particular, should be tied to supports to prevent them breaking. Old early flowering Clematis can be cut back hard if necessary.

Check your Roses regularly for greenfly, black spot and mildew. Multirose is very effective if applied early and regularly enough.

Remove dead flower heads from roses regularly.

Magnolias can be pruned this month.

Floppy border plants will need support to prevent them falling all over the place. There are lots of devices on the market to help with this or you may prefer to make your own with natural materials.

Box hedging and topiary are best trimmed this month. Mix the clippings with lawn mowings to improve the compost you make.

Check grafted plants for suckers growing from the rootstock. If left, they can rapidly outgrow the top of the plant. Check roses, fruit trees, Viburnums, lilacs, maples and most ornamental trees. Remove the suckers as close to the roots as possible so that there is no stump left from which more suckers can grow.

Make certain that newly planted trees and shrubs are getting enough water and that it is actually reaching the roots! Trees need a minimum of two gallons a week.

Snap off dead flowers from Rhododendrons and Azaleas. This will tidy them up and improve their shape. Trim over long shoots on Camellias. All these must be watered and fed well now as next year’s buds are already forming! Lookout for “False Bloom” infection.

Wildlife & Plants

Don’t forget to keep plenty of water out for the birds to drink and to bathe in regularly. A shallow container out of reach of cats is best.

Continue feeding the birds but if you feed peanuts make sure that the mesh prevents whole nuts being removed.

Use Growing Success Advanced Slug Killer or nematodes to control slugs. We have been especially impressed with the first and our treated areas in the nursery have frogs and birds everywhere!

Check hedges for nests before trimming them. If there are nests there, delay until fledglings have flown.

Grow plants with simple, single flowers to encourage insects. Not only are they interesting but they also are food for many other forms of wildlife.

Don’t rush to tidy up wildflowers after they have finished flowering. Let them spread their seed before you do.

Greenhouse

If greenhouses are getting too hot, paint ‘Coolglass’ on the outside to reflect the sun’s heat. This is easily wiped off in autumn. Wetting the floor regularly will also lower the temperature but don’t do it late in the day.

Ventilate your greenhouse on a regular basis. If it is still too hot inside, keep the doors open too.

It is usually at this time of year that whitefly and red spider mite populations in the greenhouse explode so, before that happens, order some natural predators to control these difficult pests the natural way.

Regularly remove side shoots from Tomato plants [unless you have a bush variety] and gradually increase watering and ventilation as they grow bigger and the days get warmer. Support plants well and gradually remove the lower leaves as they turn brown.

If you haven’t already done it put Cymbidium orchids, Yucca, Ficus, citrus and even cacti outside for the summer. Most will noticeably benefit but avoid full sun to start with.

If pests appear come and talk to us about using natural predators before you automatically reach for the sprayer.

The Inside Garden

Some indoor plants that have outgrown their pots will benefit from being potted on into larger pots this month. Don’t be afraid to knock plants out of their pots to take a look at how the roots are doing.

Many indoor plants will benefit from the summer outside! Make sure that they are put in a shady spot and watered well.

Softwood cuttings of a very wide range of varieties can be taken now. Difficult to root varieties could be propagated by layering.

Grow Your Own Food

Make sure that your potatoes don’t run short of moisture at this time. The new tubers should be forming now and will respond well to a thorough watering.

Plant out those annual herbs that often resent being planted too early. Basil will prefer a very sheltered spot, I grow mine in the greenhouse between my Tomatoes and a few leaves can be gathered to go with the tomatoes as I pick them.

Plant outdoor Tomatoes, Ridge Cucumbers, Courgettes and Marrows. These can all be easily grown in large pots or grow bags on the patio.

Most Herbs will benefit from being cut fairly hard now. The young shoot tips are generally the tastiest parts to use in cooking.

There is still time to make a sowing of Perpetual Spinach Leaf Beet. This is a really useful vegetable that can be harvested right through the winter.

A late sowing of Parsley can still be made and, even if you don’t have a veg. patch, Curled Parsley will not look out of place in the flower border!

Spray your apples with Bio Spray Day or Bug Clear to stop Codling Moth grubs boring into your fruit. Pheromone traps, now widely available, give good biological control but need to be installed early enough.

First early potatoes should be ready for lifting now! If there are flowers showing and the leaves are starting to go yellow, that’s a sure sign that there are big enough tubers underneath to lift. Take them straight to the kitchen, boil them with a sprig of fresh mint and serve with lashings of butter!

Bits & Pieces

Check Sweet Peas and Broad Beans for green and black fly. Use a spray such as Bug Clear or Provado Ultimate Bug Killer.

Soils, Mulching, Weed Control, etc.

Regular hoeing, especially during dry weather, will keep weeds under control and stop all but the most determined perennial weeds from getting established.

Persistent perennial weeds such as couch grass, thistles, bindweed and ground elder should be treated with Resolva 24H or Roundup now. However, ground elder will need several applications to really kill it. Don’t be tempted to cut them back before application, because the more lush the leaves are the more likely you are to get a good result. Roundup Weedkiller Gel is great for dabbing on leaves when weeds are amongst your plants!

Mulch fruit and vegetables generously.

Treat bindweed now with Roundup. Several applications may be necessary.

Ponds and Bog Plants

Oxygenating weed in ponds may be getting out of hand now so thin it out but always try to leave at least a third of the water surface covered to provide shade and shelter for wildlife.

Plant water lilies this month.

Make sure that water margin and bog plants are getting enough water and add mulch to help.